Annealing stand construction



W. H. DAILEY, JR

ANNEALING STAND CONSTRUCTION 2 Sheets-Sheet l Filed 001;. 26, 1945 F'IE2- Apri 18, i950 w. H. DAILEY, JR

ANNEALING STAND CONSTRUCTION 2 Sheets-Sheet 2 Filed Oct. 26, 1945lmeiza:

Patented Apr. 18, 1950 G STAND CONSTRUCTION William ll. Dailey, Jr.,Library, Pa., assignor to Carnegie-Illinois Steel Corporation, acorporation of New Jersey Application October 26, 1945, Serial No.624,789

The present invention relates to improvements in coil stands forannealing furnaces.

Prior to my invention, the conventional design of furnace base for theannealing of strip steel in coiled form usually comprised a rectangularstructure fabricated of fiat steel plates and structural shapes coveredwith refractory material. Normally, one to eight coil stands weresuperimposed on this fiat steel base. The base was usually covered byone large inner cover or a number of individual inner covers in order toconfine the annealing atmosphere required. Each coil stand consisted ofa refractory pedestal, preferably of the insulating type, built up fromthe flat base and surmounted by a steel plate or cast open structure ofheat-resisting metal upon which the coils to be annealed were placed.The purpose of the steel plate or metal structure was to provide a flatsurface for maximum uniformity of load distribution to minimize thecontact pressure at the lower edges of the steel coil.

As a result of demands for increased production, the piling height ofcoils on the coil stands has gradually been increased to a presentmaximum of about ten feet. This great increase in total load, togetherwith impact loads kdue to placing of the upper coils, causes rapidfailure of refractories in the coil stand. Stronger and more denserefractories have come into use in an attempt to solve theproblem. butthe strength was still found insufficient to withstand the loadsimposed, and the insulating value is low.

One object of my invention is to overcome the inherent defects in priorart annealing coll stands.

Another object of the invention is to provide a coil stand where thecoils to be annealed are supported entirely by metallic members of low`heat conductivity extending from the base plate, located in a lowtemperature zone, through a body or a ling of insulating material to anintermediate caring plate which carries the coilsupporting structuresand is located in a high temperature zone.

A further object of the invention is to provide an annealing lstandinsulated to reduce heat losses to a minimum.

Another object is the reduction of operating delays through reducedmaintenance requirements'.

An additional object is to provide the structure and arrangement ofparts as herein shown, Vde scribed, and claimed. y

For a more complete understanding oi' the invention, reference should bemade to the following detailed disclosure, the accompanying drawings,and the appended claims.

7 claims. (ci. zes-s) In the drawings:

Figure l is a vertical longitudinal section through a portion of anannealing furnace equipped with the improved coil stand embodying theherein claimed invention. 4

Figure 2 is a plan view of the improved coil stand with the top plateand intermediate plates removed.

Figure 3 is a plan view of the intermediate plate of the coil stand,showing the supporting ribs.

Figure 4 is a vertical section on line IV-IV of Figure 3.

Figure 5 is a view similar to Figure 1, showing a preferredconstruction.

Figure 6 is a partial plan view of the stand of Figure 5.

Referring in detail to the drawings, reference numeral I0 represents anysuitable masonry foundation having a chamber I2 therein for givingaccess vto the under side of the annealing furnace. suitably supportedon the foundation is a structural steel marginal frame formed of channelirons or similar rolled structural sections il. Spanning the spacebetween the members constituting the marginal frame I4 are a pluralityof floor beams i6 to which are secured a steel or other metal door I8.Spaced from the marginal frame members il and supported on the floor I8are channel members 20, the space between the outer members I4 and themembers 20 being partially filled with a gas sealing medium such assand, indicated at 22. An outer annealing furnace cover 24 is provided,and the lower portion ZGthereof enters the body of sealing sand 22. Theouter cover includes a refractory lining 28 of conventional form and abottom frame 30 which rests on the channels 20. Suitable heating meanssuch as radiant tubes or other conventional form of heating deviceforming no part of the present invention will usually be incorporated inthe outer cover 24.

The herein claimed invention is directed to the' construction andarrangement of parts constituting an improved type of coil standindicated as a whole at 32 in Figures 1 and 5. The coil stand,offFigures 1 to 4 includes a steel or other metal Ibottom plate 3l. anouter annular steel shell 36 and an inner steel shell 38 concentricthereto and spaced inwardly therefrom by a ring 40 which spans the spacebetween the shells, this ring being welded or otherwise secured theretoat its edges. A top ring l2 is welded or otherwise secured to theL upperedge of the inner shell 38. as shown.

A multiplicity oi uprights M, which may take` the form of short lengthsof pipe formed of metal of low heat conductivity, are arranged, forexample, in four concentric rows, the vlower ends ci the pipes beingpreferably welded to the base plate 34. A illling of suitable insulatingmaterial 48 is provided so as to actas a barrier to prevent the escapeof heat through the base of the apparatus. Instead of the pipes 44 I mayuse a series of rings as more fully described hereinafter, in connectionwith Figures and 6.

Loosely supported jointly by the top ring 42 and the upper extremitieso1' the multiplicity of uprights 44 is a relatively heavy metalintermediate plate 48 having integrally formed thereon a multiplicity ofupstanding radial ribs 50 jointly constituting -a supporting grid for arelatively thick top plate 52 which loosely rests on the gridlikesupport. The top plate 52 forms a seat for the lowermost one of aplurality of coils 54 of steel strip, these coils constituting thecharge of material to be annealed in the furnace. The coils may range inwidth from approximately 24 to 36 inches, and the total height of thestack of such superposed coils may be as much as ten feet. Such a stackof steel coils imposes a heavy static load on the apparatus, and the actof loading or stacking the coils from an overhead crane or the likeimparts severe live loads to'the supporting stand. The stand, having thedetailed characteristics shown and claimed herein, is peculiarly wellsuited to bear the heavy loads involved and to resist the shocks andstrains incident to charging the furnace.

The stack of coilsto be annealed is 'enclosed by an inner cover 56 ofconventional form whose lower end enters the space between the shells 36and 38 and is embedded in a body of sealing sand 68, the lower end ofthe inner cover taking its bearing on the upper face oi' the metal ring4U. The base plate 34, the intermediate plate 48, and the top plate 52are all substantially circular in plan as shown, and are provided withcentral apertures adapted to accommodate fan mechanism.

As shown by way of example in the drawings, there is a housing 8c havinga ange 62 secured to the base plate 34. The housing 6d supports a fandriving mechanism indicated conventionally at 64. This mechanism may beregarded either as a direct drive motor or as an enclosure for a pulleydriven by a suitable motor. The fan driving mechanism is adapted torotate a fan impeller 66 located in the region of the central openingformed in the top plate 52 so as to induce circulation of gas throughthe space between the top plate 52 and the intermediate plate 48 andthrough the central void or opening 68 in the stack of superposed coilssupported on the stand.

Suitable openings are provided in the base plate 34 and in theintermediate plate 48 for the passage of a pipe 10 adapted to beconnected with a source of deoxidizing gas, this pipe hav- `ing alaterally extending elbow or other tting 12 for directing thedeoxidizing gas inwardly'or toward the fan 88. Suitable pipes, one ofwhich is indicated at 14, are provided to facilitate the withdrawal of asample of the gaseous atmosphere from the interior of the inner cover56, for analytical purposes, and holes 16 may be provided for theintroduction of thermocouples.

In the described structure, because of the nonrigid or loose associationof the intermediate plate 48 with respect to the uprights/ 44 forming anintegral part of the base. the parts are tree to move relatively to oneanother. under iniiuence of expansion or contraction due to heatvariations. Likewise, because the top plate 82 is loosely or non-rigidlyassociated with the supporting ribs 60, this part can also expand andcontract freely. The described loose relationship of the parts thusgreatly minimizes the strains heretofore induced in the structuralassemblage, due to the drastic temperature uctuationsto which thischaracter of apparatus is of necessity subjected. i

In a preferred modication, as illustrated in Figures 5 and 6, instead ofthe pipe-like uprights 44 I use a plurality ot substantially concentriccorrugated rings 44, the corrugations of the rings endowing them withadded strength. These rings, like the uprights 44 above referred to, arepreferably made of metal of low heat conductivity such as stainlesssteel or nickel-chrome alloy. In this modification it is contemplatedthat instead of a loose illling o f heat insulation, as in Figure 1, thebody 46 may be of a solid substance castor molded around the severalrings 44. Thus in this construction of Figures 5 and 6 the shells suchas shown at 36 and 38 in Figure l will be omitted. The intermediate ring48 and the top ring 42 will also be omitted, and in this modication thesupporting members 44 will ,extend upwardly beyond the top surface ofthe insulation body 46, and a plain ilat plate 62 may be looselysupported by the top edges of the several rings 44a. The body ofinsulation 46 may be formed with a suitable centra1 aperture toaccommodate a fan, but the fan may be omitted if desired. The lowermostcoil to be heated in the pile may rest directly on the plate 52, and inthis modii'lcation the bottom of the inner cover 56, instead of restingon the stand, may surround the stand and rest directly on the oor platei8. as shown.

The bottom of the ystand in the modiilcation y of Figure 5 will be aplain ilat disc-like plate 34 which will rest loosely on the oor platei8. The several corrugated plates 44 may be spot welded to the plate 34at spaced intervals, merely to facilitate-assemblage of the parts. Spotor tack welding at widely spaced points is to be preferred to anintegral union, so that there will be a low degree of heat transferbetween the concentric rings d4 and the base plate 34, an importantcharacteristic of the stand being to provide good structural support fora pile or stackV oi coils, using metal members constructed of suchmaterial and so associated with the parts that there will be a minimumtransfer of heat downwardly. Thus the upper part of the stand will bethe hot zone and the lower part the relatively cooler zone. Y

In both embodiments of the invention illustrated, it is apparent thatthe static load of the pile of coils undergoing annealing treatment istransmitted through the uprights 44 or 44 dlrectly to the base plate 34or 34B, and in this manner the structurally weak filling or body ofinsulating material is not called upon to perform any load-supportingfunction.

When repairs are necessary, the stand can be removed as a unit byconnecting overhead lifting tackle to fittings engaging openings in thebase plate. In thismanner the stand can be repaired whenever time isavailable. By the substitution or immediate installation of spare standswhich will usually be kept on hand, the out-of-service or non-productivetime of the furnace can be held down to a minimum. The

5 component parts of the described stand are all producible from stockmaterials capable of being handled and fabricated economically, and theassembled stand is of rugged construction especially well suited forwithstanding operating conl. A stand of the character herein described,A'

comprising a base plate adapted to rest on an annealing furnace iioor, amultiplicity of` uprights secured to said base plate, spaced mara ginalshells surrounding said uprights, an intermediate cover ring secured toand spanning the space between said spaced shells, a filling of heatinsulating material coniinedabout said uprights i by said shells andvsaid ring, and supporting means for coiled material to be annealedincludf ing upper and lower loosely associatedplates spaced apart byribs projecting from one of said plates, said supporting means beinglocated dif rectly above and transmitting its load by means of saiduprights to said base plate.

2. A stand of the character herein described, comprising a base plateadapted to rest on an annealing furnace floor, a multiplicity of metalpipes welded at their lower ends to said base plate, spaced marginalshells surrounding said uprights, an intermediate cover ring secured toand spanning the space between said spaced shells, a filling oi.' heatinsulating material confined about said uprights by said shells and saidring, and supporting means for coiled material to be annealed includingupper and lower loosely associated plates spaced apart by a plurality ofradial ribs integral with and projecting upwardly from said bottomplate, said lower plate being supported on top of said uprights, saiduprights being of sumcient number and strength to transfer the load ofsaid coiled material to said base plate. f

3. The stand dened in claim -l, wherein said shells and said base plateare substantially circular, the said bottom plate and the saidsupporting means all being centrally apertured. a ian adapted to inducecirculation of gas from the space between said upper and lower platesand through the aperture in the center of said upper plate, fan drivingmeans located below said base plate, and a housing secured to said baseplate and supporting said fan driving means, part of said housing beingaccommodated in the apertured portions of said base plate and said lowerplate.

4. A stand of the character herein described,

comprising a metal base plate adapted to rest on coiled material to beannealed, the said uprights being oi' suiiicient number and strength totransfer the load of said lcoiled material to said base plate.

5. A stand ofy the character herein described, comprising a metal baseplate adapted to rest on an annealing furnace iloor, a multiplicity ofcorrugated rings formed of metal of low heat conductivity and supportedon top oi said base plate, a body of non-metallic heat insulatingmaterial supported on the base plate andvin which said ring-likesupports are embedded, and supporting means for coiled material to beannealed seated loosely on the lupper extremities of the said rings, thesaid corrugated rings being of sumcient strength to transfer the loadoi' said coiled material to said base plate.`

6. A stand ofthe character herein described. comprising a base plateadapted to rest onvan annealing furnace floor, a plurality ofsubstantially concentric rings made of metal of low heat conductivityeach secured to said base plate at spaced intervals, a body ofnon-metallic heat insulation resting on said base plate, said ringsbeing embedded in said body of insulation, and supporting means forcoiled material to be an-l nealed including a plate resting on theupperextremities of said rings so as to relieve said body of insulation ofthe static load of the coils to be annealed, the said concentric ringsbeing of sufflcient strength to transfer the load of said coiledmaterial to said base plate.

7.A A stand of the character herein described, comprising a base plateadapted to rest on an annealing furnace floor, a multiplicity oi.'uprights supported on top of and secured to said base plate, spacedmarginal shells surrounding said uprights, an intermediate cover ringsecured to and spanning the space between said spaced shells, a fillingof heat insulating material conilned about said uprights by said shellsand said ring, and supporting means for coiled material to be annealedincluding upper and lower loosely associated plates spaced apart byribs4 projecting from one of said plates, the said lower plate beingsupported on top of said uprights, the vsaid uprights being ofsuilicient number and strength to transfer the load of said coiledmaterial to said base plate.

WILLIAM H. BAILEY, Jn.

REFERENCES CITED The following references are 'of record in the file ofthis patent:

UNITED STATES PATENTS Fisher Aug. 25, im

